Solve 9/8+18/5-7

$$\frac{ 9 }{ 8 } + \frac{ 18 }{ 5 } -7$$

Evaluate

$$-\frac{91}{40}=-2.275$$

Solution Steps

Least common multiple of 8 and 5 is 40. Convert \frac{9}{8} and \frac{18}{5} to fractions with denominator 40.

$$\frac{45}{40}+\frac{144}{40}-7$$

Since \frac{45}{40} and \frac{144}{40} have the same denominator, add them by adding their numerators.

$$\frac{45+144}{40}-7$$

Add 45 and 144 to get 189.

$$\frac{189}{40}-7$$

Convert 7 to fraction \frac{280}{40}.

$$\frac{189}{40}-\frac{280}{40}$$

Since \frac{189}{40} and \frac{280}{40} have the same denominator, subtract them by subtracting their numerators.

$$\frac{189-280}{40}$$

Subtract 280 from 189 to get -91.

$$-\frac{91}{40}$$

Factor

$$-\frac{91}{40} = -2\frac{11}{40} = -2.275$$